Bottom sampler

ABSTRACT

This invention relates to apparatus for obtaining forceful motion and more particularly relates to apparatus for obtaining forceful motion underneath a body of water. In particular, a bottom sampler has a piston actuated by hydrostatic pressure, which upon contact of the sampler with the sea floor, drives a hollow tube into the sea floor for collecting a sample. An explosive detonator triggered by contact with the sea floor adds to hydrostatic pressure to rupture a diaphragm and actuate the piston.

United States Patent Inventor Vlash A. Pullos Garden Grove, Calif. Appl. No. 795,748 Filed Sept. 18, 1968 Patented Feb. 9, 1971 Assignee North American Rockwell Corporation Division of Ser. No. 507,904, Nov. 15, 1965, Patent No. 3,439,537,

BO'ITOM SAMPLER 3 Claims, 1 Drawing Fig.

US. Cl 175/6 Int. Cl. E21b7/12, E21b 25/00 Fieldzof Search 78/170; /261, 36, 51; 175/5, 6, 245

References Cited UNITED STATES PATENTS 2,176,477 10/1939 Varney 175/6 .92; f I A 3,118,417 l/l964 Stanwick l/6X 3,299,969 1/1967 lnderbitzen /245X 3,331,453 7/1967 Kermabon 175/6 3,370,566 2/1968 Dorr et al. 175/6X Primary Examiner-Marvin A. Champion Assistant Examiner-Richard E. Favreau Att0rneysWilliam R. Lane, Allan Rothenberg and Richard D. Seibel ABSTRACT: This invention relates to apparatus for obtaining forceful motion and more particularly relates to apparatus for obtaining forceful motion underneath a body of water. In particular, a bottom sampler has a piston actuated by hydrostatic pressure, which upon contact of the sampler with the sea floor, drives a hollow tube into the sea floor for collecting a sample. An explosive detonator triggered by contact with the sea floor adds to hydrostatic and actuate the piston.

pressure to rupture a diaphragm PATENTEU FEB 9:971

INVENTOR.

ATTORNEY BOTTOM SAMPLER This is a division of application Ser. No. 507,904, filed Nov. 15, i965, now Pat. No. 3,439,537.

In many operations beneath the surface of the ocean or other bodies of liquid it is often desirable to obtain a forceful motion to perform useful work. Thus it may be desirable to release ballast from an underwater vehicle to cause the vehicle to rise to the surface. It may be desired to cut cables or other structures or it may be desirable to pierce the ocean floor in order to obtain a sample thereof. It may also be desirable to actuate an electrical switch or other device at a selected condition. In any of these instances a single rapid operation of a unit is required rather than a series'of repetitive operations. In the past such operations have been conducted by the use of compressed gases, gravity actuation or explosive charges. Each of these are subject to certain limitations or dangers in operation. Thus, for example, gravity operated devices are limited in the total force applied and also in the rate at which force can be applied. Actuators employing compressed gases or explosives are dangerous for handling on shipboard. Other pressure operated actuators give a relatively slow motion that is impractical for many desired operations.

it is therefore a broad object of this invention to provide a safe reliable actuator for underwater operations.

Thus in the practice of this invention according to a preferred embodiment there is provided an underwater core sampler comprising a piston in a housing, a frangible diaphragm for admitting external pressure on one side of the piston for compressing a gas on the opposite side of the piston, and a substantially tubular member connected to the piston and extending through at least one end of the housing.

Thus it is a broad object of this invention to provide an actuator for obtaining a forceful motion beneath a body of liquid.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompany drawing which: illustrates in cross section a core sampler for obtaining samples of the ocean floor.

The drawing illustrates a core sampler constructed according to the principles of this invention for obtaining a long core from an ocean bottom or the like. As illustrated in this embodiment there is provided a cylindrical housing 81 within the bore of which is a slidably movable piston 82 that serves to divide the interior of the housing into a first gas filled chamber 83 and a second chamber 84. An elongated core tube 86 is formed on the piston so as to extend along the axis thereof from both sides of the piston and through the ends of the housing 81. The bore of the core tube 86 extends through the piston. O-ring seals 87 are provided between the core tube and the housing 81 to prevent ocean pressure from entering the chambers 83 and 84 respectively. In addition an O-ring seal 88 on the piston 82 prevents leakage between the two chambers 83 and 84. A conventional piercing point 89 of hardened, sharpened material is threaded on the end of the core tube 86 at the bottom thereof for piercing the ocean floor and recovering a core therefrom.

The lower end of the housing 81 has a drag apron 91 formed as an integral part thereof. it should also be noted that the drag apron 91 can comprise a plurality of segments hinged to the housing in order to obtain better sinking characteristics. Cables or wires 92 are connected between the housing 81 and the drag apron 91 to serve as strengthening for the drag apron during use of the core sampler.

Also attached to the housing near the bottom is a contact switch 93 that is actuated by a rod 94 extending through the drag apron 91 to a point somewhat beyond the piercing point 89 on the core tube. The switch 93 is actuated by pressure on the end of the rod 94 as hereinafter described. At the upper end of the housing 81 and transverse to the length thereof is a side opening that is sealed by a frangible diaphragm 96. The diaphragm is secured in place against the housing by a spacer 97 and a threaded nut 98. An electrically fired explosive detonator 99 is cemented or otherwise attached to or near the diaphragm 96 to provide an extra pressure wave when desired. The detonator is electrically connected to the switch 93 and a battery (not shown) by means of wires 101 so that upon closing of the switch 93 the explosive detonator is fired. It will also be apparent that a solenoid driven punch could pierce the diaphragm to initiate rupture.

An eye bolt 102'is attached to the upper end of the housing 81 and a cable 103 is secured to the eye bolt so that the core sampler can be recovered from the ocean bottom after use. it may also be desirable in some embodiments to employ a drag device such as a sea anchor on the cable 103 at some point above the core sampler to assure that the core sampler sinks toward the bottom in a substantially upright position.

in order to operate the core sampler described and illustrated in the drawing the piston 82 is positioned in the housing 81 as illustrated in the drawing. This operation and sealing of the diaphragm 96 are done at the surface of the ocean so that the chambers 83 and 84 are both filled with air at substantially atmospheric pressure. If it is desired, the chamber 84 can be filled with a fluid other than air, such as water, however, it is preferred to fill the chamber 84 with air to maintain the center of buoyance high and assure sinking in an upright position.

After assembly the core sampler is lowered or permitted to sink to the bottom of the ocean and when contact is made with the bottom by the rod 94 the switch 93 is closed thereby igniting the explosive detonator 101. The pressure wave generated by the explosive detonator, added on to the hydrostatic pressure due to the head of water above the core sampler, is sufficient to rupture the frangible diaphragm 96. This admits ocean pressure to the chamber 84 so that the ocean pressure can act on the face of the piston 82. This forces the piston 82 downwardly against the air in the chamber 83 thereby compressing the air and driving the core tube 86 downwardly through the housing. Due to the substantial weight of the housing relative to the core tube and also due to the high drag of the drag apron 91, the piercing point 89 is driven into the ocean floor, thereby cutting a core that is collected within the bore of the core tube 86. Water within the core tube 86 is expelled from the top thereof and if it is desired a screen or other restriction can be placed at the too to prevent the loss of loose solid material associated with the core. it is found that the very high drag of the drag apron 91 substantially prevents any upward motion of the core sampler during stroking of the piston and driving of the core tube into the ocean bottom since the time required for the piston to stroke is relatively short. A high load is imparted to the drag apron 91 and the cables 92 are provide to prevent the drag apron apron from being broken off at the housing. After the core tube 86 has been driven into the ocean floor and a core collected, the entire assembly is lifted by means of the cable 103 and returned to the vessel from which it was dropped. The core is then readily removed for study.

in a typical core sampler the core tub has a ZVzinch outside diameter and the piston has an inside diameter of 6 inches. At a pressure of 200 p.s.i. corresponding to a depth of about 450 feet the core sampler develops an initial force of about 2 l ,600 pounds, and even at percent of the stroke the driving force on the piston is in excess of a ton. The forces are proportionally larger at greater depths and other proportidns of core tube and piston can be employed to give a. suitable force at any selected depth. it is found with a device of this sort that core samples as long as 20 feet can be obtained in ocean bottoms comprising typical silt and mud.

it will be apparent that in lieu of a tube extending from the piston out of the bottom end of the housing, a rod can be employed. Such a rod driven into the mud of the bottom provides an excellent anchor since it is quite resistant to lateral forces. Such an anchor can be withdrawn b by a vertical lift, or can be left implanted in the bottom. Similarly, a plurality of parallel rods can be employed in an anchor or barbed ends can be provided on the rods to resist vertical withdrawal from the ocean bottom.

It will be apparent to one skilled in the art that many substitutions, modifications, and variations can be made in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

lclaim:

1. Apparatus for obtaining a single, rapid, forceful movement at a selected high pressure comprising:

a housing having a cylindrical bore;

a piston movably mounted in the bore of said housing sealably dividing the bore into a first closed chamber on one side of said piston and a second closed chamber on the other side of said piston;

a frangible diaphragm in said housing adjacent the second chamber or excluding external pressure from the second 

1. Apparatus for obtaining a single, rapid, forceful movement at a selected high pressure comprising: a housing having a cylindrical bore; a piston movably mounted in the bore of said housing sealably dividing the bore into a first closed chamber on one side of said piston and a second closed chamber on the other side of said piston; a frangible diaphragm in said housing adjacent the second chamber or excluding external pressure from the second chamber; an explosive detonator disposed adjacent said frangible diaphragm for momentarily raising pressure on said diaphragm for initiating rupture thereof; and a sensor actuated by contact with a surface for detonating said explosive detonator.
 2. An underwater core sampler including an apparatus as defined in claim 1 and further comprising a substantially tubular member connected to said piston and extending through at least on end of said housing.
 3. An apparatus as defined in claim 2 and further comprising a drag member for inhibiting rapid rise of said actuator in water. 